Aluminum interaction with plasma membrane lipids and enzyme metal binding sites and its potential role in Al cytotoxicity
Aluminum interaction with plasma membrane lipids and enzyme metal binding sites and its potential role in Al cytotoxicity
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DOI：
10.1016/s0014-5793(96)01319-1
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发表时间：
1997-01-02
期刊：
影响因子：
3.5
通讯作者：
Kochian, LV
中科院分区：
文献类型：
--
作者：
Jones, DL;Kochian, LV
三价阳离子铝可引起植物、动物和微生物的慢性细胞毒性。有人建议,Al与细胞膜和金属结合位点的酶可能参与细胞毒性,在这项研究中,绑定的微粒体和脂质体被发现脂质与信号转导相关元素phosphatidylinositol-4 5-bisphosphate拥有最高的亲和力Al的艾尔:脂质化学计量的1:1,艾尔绑定只是减少高浓度的Ca2 +的存在(> 1毫米),柠檬酸和,在较小的程度上,研究了AlCl3、Al-柠檬酸盐和ZnSO4对金属依赖性酶（烯醇化酶、丙酮酸激酶、H+- atp酶、肌球蛋白、钙蛋白酶、蛋白酶K、磷脂酶a(2)和精氨酸酶）活性的影响，发现Zn2+能抑制除H+- atp酶外的所有酶。除了与AlCl3相互作用的磷脂酶A(2)外，AlCl3和Al-柠檬酸盐的作用很小，然而，柠檬酸盐的加入可以消除这种作用。结果表明，与目前的假设相反，Al的毒性模式不是通过与酶催化金属结合位点的相互作用，而是通过与特定膜脂的相互作用。
The trivalent cation aluminum can cause chronic cytotoxicity in plants, animals and microorganisms. It has been suggested that Al interaction with cell membranes and enzyme metal binding sites may be involved in Al cytotoxicity, In this study, the binding of Al to microsomes and liposomes was found to be lipid dependent with the signal transduction element phosphatidylinositol-4,5-bisphosphate having the highest affinity for Al with an Al:lipid stoichiometry of 1:1, Al binding was only reduced in the presence of high concentrations of Ca2+ (>1 mM), Both citrate and, to a lesser extent, malate were capable of preventing Al lipid binding, which is consistent with the involvement of these organic acids in a recently described Al detoxification mechanism in plants, The effects of AlCl3, Al-citrate and ZnSO4 on metal-dependent enzyme activities (enolase, pyruvate kinase, H+-ATPase, myosin, Calpain, proteinase K, phospholipase A(2) and arginase) was assayed in vitro, While Zn2+ was capable of inhibiting all the enzymes except the H+-ATPase, AlCl3 and Al-citrate had minimal effects except for with phospholipase A(2) where an interaction with AlCl3 occurred, However, this could be negated by the addition of citrate, The results indicate that, contrary to current hypotheses, the toxic mode of Al is not through an interaction with enzymatic catalytic metal binding sites but may be through the interaction with specific membrane lipids.